Honestly, the way I read it was that payments wouldn't stop once the ROI hit 300%, just that it was a guaranteed ROI of 300% over 2 years. So theoretically, depending on how popular these are, we could get a 300% ROI in a year or less, and payments would continue until that 2 year period was up.
With that being said, I am curious to see how they react to people who are unhappy about these terms. Here's hoping for the best.
The first bullet point states otherwise. It seems pretty clear to me that once 300% ROI is hit you are done. Here is the full post
https://bitcointalk.org/index.php?topic=324225.msg3480030#msg3480030- 300% ROI is Guaranteed within 2 years, after which the ownership of the machine reverts back to us.